A rotating reinforced plastic belt loop has been used in textile plants to form a tensioned span pressed against a rotating rigid metal counterroll to form a nip through which textile filaments are propelled at high velocity. The filaments are impressed or less into the belt surface, and this, with the high velocity, subjects the belt to high mechanical stresses. The filaments may be treated with a scrooping agent which can chemically affect the belt's surface.
To meet the above conditions, a polyurethane elastomer having a surface hardness of 60 to 95 Shore A when hardened, and composed of an NDI or TDI and polyester or polyether, is satisfactory as the plastic component.
To provide reinforcement for the plastic, it is old to use fiber gauze in the form of a flat length which is impregnated with a solution of the plastic, dried from the solution's solvent and then wrapped around a core, necessarily with overlapped ends. With the core and reinforcement in a mold, the plastic is cast and hardened to form the belt loop.
The above technique has the disadvantage that to avoid the overlapping causing excessive thickening and introducing dynamic unbalance when the belt loop is in high speed operation, extremely light fiber gauge must be used, such as having an area weight between 10 and 50 g/m.sup.2. Liquid casting plastic impregnation is uncertain and the reinforcement strength provided is subject to question. The weight and strength of the reinforcement cannot be increased appreciably because this would increase the overlap with its attendant alteration in the overall flexibility of the belt and in the balance of the belt loop when operating. An undesirable number of manufacturing steps are used.